1. Field of the Invention
This invention relates to a disc cartridge, and more particularly to a disc cartridge which has a hard disc, particularly, a double-sided type hard disc housed in a casing.
2. Background of the Invention
In general, a disc-type data recording carrier such as a compact disc (CD), a video disc (LD) or the like is used in a manner to be removed from a packing case and set in a recording and/or reproducing equipment.
Conventionally, protection of such a disc type recording carrier from the environment has been desirable because it is not only easy to become covered with dust and damaged but also adversely affected due to a variation in temperature. For this purpose, the use of an envelope such as a tray, a casing or the like has been proposed to protect the disc. Unfortunately, such a conventional envelope is not suitable for the protection of a double-sided hard disc, because the housing of the disc in a storage space defined in the envelope causes the disc to be contacted by the envelope. Also, the formation of a cutout or slot at the envelope which is indispensable to the operation of a disc cartridge results in foreign matter such as dust or the like entering the disc cartridge through the slot to pollute the disc. Further, the envelope causes the disc to be contacted by an inner surface thereof during the storage or transportation. Thus, the use of the envelope results in damage and/or pollution of the disc as well as the exposure of the disc to a variation in temperature.
Accordingly, it would be highly desirable to provide a disc cartridge which is capable of not only safely housing disc in a casing but preventing a foreign matter such as dust or the like from entering the disc cartridge to keep the disc clean in the casing.